This invention relates to shoe soles and, more specifically, to an improved shoe sole that guides the foot as the user walks or runs with a shoe incorporating the improved shoe sole.
Shoe soles are well known in the prior art. Soles made of a resilient material provide additional comfort for the user and store a portion of energy generated during a step or stride. Shoe soles, however, have not been produced that conform the sole to the natural walking or running pattern of a foot engaging the ground. That is, the prior art soles do not guide the foot along a natural walking or running path of a user of the sole. If the sole were to accommodate the natural pattern of a foot engaging the ground, the comfort and efficiency of a sole could be improved.
A foot typically contacts the ground at the outer portion of the heel. As the step advances, a greater portion of the heel, along with the outer portion of the arch of the foot, then contacts the ground. Next, the inner portion of the ball of the foot contacts the ground. Following the contact by the inner ball of the foot, the remainder of the ball of the foot and the toes contact the ground. At this point, the foot is generally flat on the ground. As the heel begins to leave the ground, weight is transferred to the ball of the foot. After the heel and arch leave the ground, most of a person""s weight is concentrated on the inner portion of the ball of the foot. As the foot begins to leave the ground, the inner portion of the ball of the foot and the big toe are the last areas to be in contact the ground. The above described natural pattern of contact between the foot and the ground can, generally, be called an S-shape path. That is, as a step advances, the point of contact is, in order, at the following locations: the heel, the outer arch, the inner ball, and the outer ball.
Prior art soles do not provide a means for guiding the foot along this natural path. Prior art soles may have protruding portions which are designed to constitute an elastic shock absorber so as to be able to absorb the impact that typically occurs during walking or running, for example. However, these protrusions typically force the foot away from the natural S-shaped path. That is, prior art protrusions create zones that pull the foot away from the natural path, force early pronation, and/or force the foot to move internally. While these protruding portions may be helpful for their intended purpose, efficiency and comfort could be improved by taking advantage of the natural S-shaped path or pattern of a step.
There is, therefore, a need for a sole having protrusions structured to induce or to force a guided sequence of movement of the foot from the instance when the heel contacts the ground to the instance when the big toe leaves the ground to improve walking comfort of a user of the shoe sole.
Within the scope of this aim, a particular object of the invention is to provide a sole which, in a way, induces the foot to gradually move along a path outlined on the basis of the classic concepts of biomechanics applied to walk analysis.
Another object of the present invention is to provide a sole for shoes with foot guiding means which, by virtue of the particular constructive characteristics of the sole, is capable of providing the greatest assurances of reliability and safety during use.
Another object of the present invention is to provide a sole which can be altered, in each instance, according to the specific sport or activity for which it is applied and according to the type of movement to be performed.
These and other needs are solved by the invention which provides a sole having, on the sole lower surface, a plurality of protrusions structured to force a guided sequence of movement of the foot from the instance when the heel initially contacts the ground to the instance when the big toe breaks contact with the ground. The protrusions on the lower surface are made from a resilient material and include some protrusions that are more flexible than other portions which tend to be more rigid. That is, the material that forms the protrusion may have a different areas or sections with different resiliencies. Alternatively, the protrusions may be located opposite or adjacent to an air chamber in the sole so that, during a stride, the protrusion may flex inward into the air chamber. Alternatively, the protrusions may be angled in a desired orientation or arrangement to facilitate guiding the foot along a desired guided sequence as well. The orientation of the angled surfaces, the location of the air chambers, the size and/or orientation of the less resilient portions may vary, from application to application, so that the protrusions are programmed to have a pivot or bend axis, extending in a desired direction, to promote the natural or intended path. That is, for a sport where the user is more likely to move side to side, e.g. tennis, the some or many of axes may extend, generally, in the direction of the longitudinal axis of the sole. However, where the user is more likely to move generally forward, e.g. running, the axes of the protrusions will extend generally perpendicular to the longitudinal axis of the sole.
Generally, there is at least one protrusion located at the rearward most portion of the heel portion of the sole, as well as other protrusions located along the outer side of the heel portion, and protrusions on the inner and outer sides of the ball of the foot portion promote the desired the path or guidance sequence of the foot.
Further characteristics and advantages will become apparent from the description of preferred but not exclusive embodiments of soles for shoes with foot guiding means.